Elsevier

Neuroscience Letters

Volume 89, Issue 3, 8 July 1988, Pages 286-292
Neuroscience Letters

An intracellular analysis of amino acid induced excitations of deep dorsal horn neurones in the rat spinal cord slice

https://doi.org/10.1016/0304-3940(88)90541-1Get rights and content

Abstract

The rat spinal cord slice preparation has been used to investigate the sensitivity of deep dorsal horn neurones to the excitatory amino acids N-methyl-d-aspartate (NMDA), quisqualate and l-glutamate. Intracellular recordings were made from 44 neurones in laminae III–VI of 14- to 16-day rats. Superfusion of quisqualate (30 μM) excited all neurones, NMDA (50 μM) excited 72% and l-glutamate (0.5–1 mM) 63% of the neurones. Depolarizations were retained after tetrodotoxin but with a reduced amplitude. The NMDA antagonist d-aminophosphonovalerate (d-APV, 10 μM) reduced NMDA and l-glutamate depolarizations by 66% and by 40%, respectively, while the quisqualate responses were enhanced by 27%. Dorsal root stimulation elicited two main patterns of activity; short-latency single/double spikes followed by subthreshold excitatory postsynaptic potentials (EPSPs) or a burst of spikes rising from a long duration composite EPSP. d-APV reduced the long-latency components of the first type and reduced the amplitude and duration of the composite EPSP of the second. These results support a specialized role for NMDA receptors in synaptic transmission in the dorsal horn.

References (20)

  • G. Bernardi et al.

    Intracellular studies on the action of L-glutamic acid on spinal neurones of the cat

    Brain Res.

    (1972)
  • S.P. Schneider et al.

    Selective excitation of neurons in the mammalian spinal dorsal horn by aspartate and glutamate in vitro: correlation with location and excitatory input

    Brain Res.

    (1985)
  • V.J. Balcar et al.

    Glutamate uptake by brain slices and its relation to depolarization of neurones by acidic amino acids

    J. Neurobiol.

    (1972)
  • A.J. Cook et al.

    Dynamic receptive field plasticity in rat spinal cord dorsal horn following C-primary afferent input

    Nature (Lond.)

    (1987)
  • R. Corradetti et al.

    Pharmacological characterization of D-aminophosphonovaleric acid antagonism of amino acid and synaptically evoked excitations of frog motoneurones in vitro: an intracellular study

    Br. J. Pharmacol.

    (1985)
  • D.R. Curtis et al.

    Chemical excitation of spinal neurones

    Nature (Lond.)

    (1959)
  • N.S. Davies et al.

    Evidence for involvement of N-methylaspartate receptors in ‘wind-up’ of class 2 neurones in the dorsal horn of the rat

    Brain Res.

    (1987)
  • J. Davies et al.

    Selective antagonism of amino acid induced and synaptic excitation in the cat spinal cord

    J. Physiol. (Lond.)

    (1979)
  • A.W. Duggan

    The differential sensitivity to l-glutamate and l-aspartate of spinal interneurones and Renshaw cells

    Exp. Brain Res.

    (1974)
  • R.H. Evans et al.

    The effects of a series of ω-phosphonic-α-carboxylic amino acids on electrically evoked and excitant amino acid induced responses in isolated spinal cord

    Br. J. Pharmacol.

    (1982)
There are more references available in the full text version of this article.

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Present address: Department of Anatomy, University Medical School, University of Debrecen, Debrecen, Hungary.

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